Health effects of BT foods

There have been a series of scientific reports indicating side effects of transgenic Bt corn or potatoes on the animals. To quote a few:
1. In July 2008, Austrian researchers found that feeding rats a diet containing the transgenic corn NK603 x MON810 affected the reproduction of mice that was detected in 3rd and 4th generation in the reproductive assessment by continuous breeding (RACB) study design. Some effects on the kidneys were also observed.1
2. In November, 2008, Italian researchers concluded that “the consumption of Bt MON810 maize … induced alteration in intestinal and peripheral immune response of weaning and old mice.”2
3. In December 2009, Joël Spiroux de Vendômois et al., studied the rats with feeds of three main commercialized genetically modified (GM) maize (NK 603, MON 810, MON 863), which are present in food and feed in the world. They observed that it causes hepatorenal toxicity. Other effects were also noticed in the heart, adrenal glands, spleen and haematopoietic system.3
4. Mice fed potatoes engineered to produce the Bt toxin developed abnormal and damaged cells, as well as proliferative cell growth in the lower part of their small intestines (ileum).4
How can transgenic Bt food be considered “safe” when there are so many studies showing adverse effects of Bt foods? Some studies have shown adverse effects on 3rd generation at the earliest and that too by Reproductive Assessment by Continuous Breeding (RACB) study design. The toxicological studies done by Mahyco do not include studies beyond 90 days of exposure. How can we consider Bt brinjal “safe” without proper, multigeneration studies?

B. Variety of Adverse Effects Due to GM Food in General

Certain studies have shown that the GM food can change the cell structure itself! Two of them:
1. Researchers studied effect of feeding GM soybean on mice and found out that it caused significant modifications in the nuclei (irregularly shaped nuclei) in the hepatocytes of GM fed mice.5
2. Scientists studied pancreatic acinar cell nuclei on the mice fed on genetically Modified soybean. The modifications observed in pancreatic acinar cell nuclei of GM-fed mice could be related to the reduction in digestive enzyme synthesis and secretion and can influence the pancreatic metabolism in mouse.6

Several animal studies indicate serious health risks associated with GM food consumption including infertility, immune dysregulation, accelerated aging, dysregulation of genes associated with cholesterol synthesis, insulin regulation, cell signalling, and protein formation, and changes in the liver, kidney, spleen and gastrointestinal system. There is more than a casual association between GM foods and adverse health effects. Animal studies also show altered structure and function of the liver, including altered lipid and carbohydrate metabolism as well as cellular changes that could lead to accelerated aging and possibly lead to the accumulation of reactive oxygen species (ROS). One study, done by Kroghsbo et al., has shown that rats fed transgenic Bt rice trended to a dose related response for Bt specific IgA. Also, because of the mounting data, it is biologically plausible for Genetically Modified Foods to cause adverse health effects in humans.23

C. Increase in Allergic reactions

Allergic reactions occur when the immune system interprets something as foreign, different, and offensive, and reacts accordingly. All GM foods, by definition, have something foreign and different. And several studies show that they provoke reactions. To quote a few:

1. Rats fed Monsanto’s GM corn had a significant increase in blood cells related to the immune system.7
2. GM potatoes caused the immune system of rats to respond more slowly.8
3. GM peas provoked an inflammatory response in mice, suggesting that it might cause deadly allergic reactions in people.9
4. Scientists have demonstrated high immunogenicity of Cry1A proteins administered by intragastric route and cautioned the use of transgenic plants for human consumption.10
5. There have been reports of allergic reactions to Bt spray. The reaction was severe enough to cause hospitalisation in some of the cases.11,12,13
6. Bt toxin might also trigger reactions by skin contact. In 2005, a medical team reported that hundreds of agricultural workers in India are developing allergic symptoms when exposed to Bt cotton, but not when exposed to natural varieties.14

Although there may be many causes, it might be difficult to identify whether GM foods were triggering allergic responses in the population. Since our country does not conduct regular studies or keep careful records, we need to do allergic studies in great detail before GM food is permitted for human consumption.

D. GMOs are inherently unpredictable

It has been scientifically proved beyond doubt that genes are not carriers of a single trait. The effect of every gene is determined by the total situation in the cell. Therefore, the transfer of a single gene can not yield intended results and is inevitably unpredictable.

Insertion of transgene can lead to mutation, deletion and alterations of the genomic structure. All this can change RNA, protein, enzymes and other countless natural products in the organism. To cite an example,

The gene of soybean glycinin was transferred into potatoes with the aim to increase their protein content. However, the improvements in protein content or amino acid profile were minimal. In fact, the total protein content of the GM potatoes after the gene transfer became significantly less than that of the control line. Even more unfortunately, the contents of some vitamins were reduced while the amounts of both solanine and chaconine increased in the GM lines. In this light the claimed substantial equivalence of the GM and parent lines was not supported by the published results.15

As some of the changes are unpredictable and it is only possible to compare the known properties and constituents of GM and conventional plants. Unknown components are not looked for and in that case how can we analyse them?

Scientists have opined that just chemical analysis of macro/micronutrients and known toxins is at best inadequate and, at worst, dangerous. More sophisticated analytical methods need to be devised, such as mRNA fingerprinting, proteomics, secondary metabolite profiling and other profiling techniques.

Do we have facilities for this kind of studies? Are they mandatory at present? How are we going to label it safe without detailed investigations?


From Concerned Health Professionals for Biosafety in Food
January 19, 2010
To Shri Jairam Ramesh
Honourable Minister of State (Independent Charge)
Ministry of Environment and Forests
Government of India
Public Consultation on Bt Brinjal at Ahmedabad